Use Detergent Or Liquid Dishwasher: This is the most popular home remedy and the easiest one to opt for. Before going for this, just make sure that ketchup is not dried in its place because dried one will need more effort to be removed.
Use Ammonia: Ammonia has alkaline cleaning agents and is corrosive in nature, which is a great option to clean food stains such as BBQ sauce, red wine stains, etc.
Use Baking Soda: When stains are not in the mood to vanish easily, then baking soda can be your savior. Baking soda can work on such aggressive stains, which are hard to detach after drying.
Any stain needs time and effort to be removed, and it is similar in the case of ketchup as well. In this situation, you can use any home remedy like detergent or liquid dishwasher, or you can go with vinegar or baking soda to treat.
It is not easy to remove dried stains from the carpet, but not impossible to accomplish. You just need some extra effort for it, like scratching the stained region.